Conditions analysis approach to infinite stiffness for an active control aerostatic bearing

Conventional aerostatic bearings have the problems of vibrations and motion inaccuracy due to the low stiffness. To overcome these problems, the authors propose a control scheme of active control aerostatic bearing. This new type of bearing is composed of non-contact sensors to detect the radial displacement of its axis, control valve to drive the axis and a controller to regulate the whole system. When radial load is applied, the active bearing can suppress the displacement of the shaft, thus obtaining an infinite stiffness. Three kinds of control ways are presented, and corresponding numerical values of infinite stiffness are given.